Vehicles of the kind having a tiltable dump body often require reinforcing of the vehicle bed so as to rigidify the bed against deflection and torsion to which the bed may be subjected during its tilting movements. Trough-like reinforcing structures heretofore have been welded to the lower surface of the vehicle bed, but such structures have less than desirable reinforcing characteristics unless they are constructed from relatively heavy gauge sheet material which is more expensive than lighter gauge material and more difficult to handle due to the greater weight of the material. In some instances the length of the vehicle bed is so great that a fairly large number of such reinforcing troughs must be utilized if any significant reinforcing of the bed is to be achieved, as a consequence of which the weight of the vehicle is increased materially with a consequent reduction in its load carrying capacity and a reduction in its fuel efficiency.